Virtually nothing is known about the freuency of "null" allozyme alleles (alleles which code for the production of no enzyme activity) in natural populations or their importance to the well being of the individuals who carry such alleles. This study seeks to answer these questions for several natural populations of Drosophila melanogaster. Partial analysis of a sample from the Raleigh, North Carolina population of Drosophila melanogaster suggests that the frequency of "null" allozyme alleles is less than one percent per locus and varies considerably among loci.